Production of barium cyanid.



UNITED STATES PATENT OFFICE.

KARL Boson AND A'LWIN MITTASGH, on LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNQ oRs TO BADISGHE ANILIN & SODA FABRIK, or LUDWIGSHAFEN-QN-THE-RHINE, GER- MANY; A CORPORATION.

PRODUCTION OF BARIUM CYANID.

Patented Feb. 11, 19023.

To all whom it may concern:

Be it known that we, KARL Boson and ALWIN MITTASCH, doctors of hilosophy and chemists, subjects, respective y, of t e King of Prussia and the King of Saxony, residing at Lu dwigshafen on the Rhine, Germany, have invented new and useful Improvements in the Production of Barium Oyanid, of which the following is a specification.

Although Margueritte and Sourdevals rocessfor the production of barium cyanid y heating together carbonaceous material and barium oxid, or barium carbonate, in

the presence of nitrogen gas, was discovered in the year 1860 it has not hitherto been capable of being carried out on a commercial. scale owing to the small yield of barium cyanid obtained." Experiments have shown that high temperaturesare advisable, during the reaction, in order 'to cause as much nitro-' gen as possible to enter into combination, but the quantity of cyanid formed is not in proportion to the quantity of nitrogei'i comined, because at high temperatures the barium cyanid tends to split up into barium cyanamid and carbon according to the equation Ba (ON) =BaON,+O, and we have discovered that this splitting u increases as the temperature increases, whi e at lower tom eratures the reverse action takes place, arium cyanamid combining with. carbon and forming barium cyanid. It would therefore naturally be expected that, during cool .ing down from the high temperatures em ployed, the barium cyanamid present would combine with, the carbon which se arated out at those high temperaturesand t at the cold product would consist of barium cyanid with ittle, or no, barium cyanamid. This, however, is not the case, for the cold product contains a considerable quantity of bariumcvanamid, and Webelieve that this is due to the carbon which separates out fromthe barium u cyanid at hi h temperatures, separating in,

or being, subsequently converted into, aform (for instance the form of graphite) un-' suitable for being taken up agam by the barium cyanamid during cooling. We have discovered that if duringv cooling, a gas con barium cyanamid'up to, and maintainin it at, a comparatively low temperature,w ile passing the gases conteining carbon over the, said mixture. Temperatures below 1200.

O. are suitable for use in carrying out the process of our invention.

The following examples will serve to illustrate how our invention can be carried out, but it is not confined to these examples.

Example 1. Heat, in an iron vessel, at a temperature of from six hundred (600), to eight hundred (800), degrees centigrade, raw barium cyanid mixture in which, for, instance, sixty per cent. of the nitrogen contained therein is in the form of cyanid and the rest is in the form of cyanamid, and lead current of acetylene gas over the mixture thus heated. The conversion of the cyanamid into cyanid is finished in a few hours.

' Example 2. Make a mixture of three (3) parts by weight of barium carbonate and one (1) partby weight of charcoal into briquets and heat these in a chamotte vessel at a tern perature of about fifteen hundred (1500) degrees centigrade, while passingv a current of nitrogen through the vessel. As soon as no more nitrogen is being absorbed, allow the which hasbeen freed rom carbon dioxid,

through the vessel until the conversion of the cyanamid into cyanid is complete.

Now What we'claim is: 1. The conversion of barium cyanamid into barium cyanid by heating the barium cyanamid at a temperature below 1200 C. in

contaimngcarbon. A

the, presence of a hereinbefore defined gas t The: production 'of barium cyam'd by v ing barium carbonate, and carbonaceous ma heating to a com aratively high ternperature our hands in the presence of two subscribing in the presence 0 nitrogen a mixture contain- Witnesses.

, KARL BOSCH. terlal and then treatin the resultin roduct WhllB'it is cooling With a hereinbefor e defined ALWIN n A gas containing carbon, substantially as described; v

Intstirnony whereof We have hereunto set Witnesses ERNEST F. EHRHARDT, T. ALEc. LLOYD. 

